Fiber blending apparatus and method

ABSTRACT

The invention is directed to method and apparatus for blending fibers. In one aspect, the apparatus comprises blending apparatus for blending fibers of different materials, at least one of which is absorbent, and for conveying the blended fibers to a fiber collection station. A first weighing apparatus weighs out a first quantity of first fibers at a first weigh station. A second weighing apparatus weighs out a quantity of second fibers at a second weigh station. The first and second quantities of fibers are conveyed to a blend opener having a beater roll rotatable in the blend opener. The beater roll opens and mixes the fibers. The fibers are entrained in an air stream by a pneumatic conveyor system and conveyed to a fine opener. The fine opener has a rotatable clothing roll to further open and mix the fibers. The pneumatic conveyor system is operable to separate fiber fines from longer fibers and to deliver the longer fibers to said fine opener. The blended fibers can be used for making pads, such as feminine protection pads.

BACKGROUND OF THE INVENTION

The invention relates generally to a method and apparatus for blendingfibers and, more particularly, to a method and apparatus for blendingfibers used to make feminine protection pads.

This invention is especially suited for the commercial manufacture ofpads of the type shown in U.S. Pat. No. 4,595,392, entitled “InterlabialPad”, and U.S. Pat. No. 4,673,403, entitled “Method and Pad AllowingImproved Placement of Catamenial Device”, both of which are assigned toKimberly-Clark Corporation and incorporated by reference herein for allpurposes. The pads described in these patents generally comprise alamination of a layer of absorbent material (e.g., a blend of fibers,including cotton fibers) disposed between two cover layers, one of whichis fluid pervious and faces the body when the pad is in use, and theother of which is typically fluid impervious. The pad is small comparedto other feminine protection products and must be manufactured torelatively close tolerances. These size and tolerance requirements posechallenges to the efficient and economic production of this product on acommercial scale.

SUMMARY OF THE INVENTION

The apparatus and methods of the invention provide for the efficient andeconomic production of absorbent products, including but not limited torelatively small pads (e.g., interlabial pads) of the type describedabove which require relatively tight manufacturing tolerances. Suchapparatus and methods have several aspects.

In one aspect, the invention is an apparatus for blending first andsecond fibers. The apparatus includes apparatus for conveying a supplyof first fibers to a first weigh station, apparatus for conveying asupply of second fibers to a second weigh station. The apparatus alsoincludes first weighing apparatus at the first weigh station forweighing out and discharging a first quantity of the first fibers,second weighing apparatus at the second weigh station for weighing outand discharging a second quantity of the second fibers, and fiberopening and blending apparatus for opening and blending the first andsecond quantities of fibers discharged from the first and secondweighing apparatus. The fiber opening and blending apparatus includes ablend opener having a housing with an inlet for entry of the fibers andan outlet for discharge of the fibers, a beater roll rotatable in theblend opener housing for opening and mixing the fibers for dischargethrough the outlet, and a fine opener comprising a housing having aninlet for receiving fibers from the blend opener, an outlet, and aclothing roll rotatable in the fine opener housing for further openingand mixing the fibers for discharge through the fine opener outlet.

In another aspect, the invention is a method of blending first andsecond fibers. The method includes conveying a supply of first fibers toa first weigh station, conveying a supply of second fibers to a secondweigh station, weighing out and discharging a first quantity of thefirst fiber, and weighing out and discharging a second quantity of thesecond fiber. The method includes conveying the first and secondquantities of fiber to a blend opener, and opening and blending thefirst and second quantities of fibers with a first rotatable roll in theblend opener. The method further includes entraining the blended fibersin an air stream to convey the blended fibers from the blend opener to afine opener, and further opening and mixing the fibers with a secondrotable roll in the fine opener.

Other features will be in part apparent and in part pointed outhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of one embodiment of an interlabial pad made inaccordance with the apparatus and methods of the invention;

FIG. 2 is a sectional view of the pad of FIG. 1;

FIG. 3 is a view showing the pad of FIG. 1 in folded condition;

FIG. 4 is a sectional view taken in the plane of line 4—4 of FIG. 3;

FIG. 5 is a flow diagram illustrating various sections of amanufacturing process of the invention for making pads;

FIG. 6 is a flow diagram illustrating various components of oneembodiment of a fiber blending section of the manufacturing process;

FIG. 7 is an elevation of weighing apparatus of the fiber blendingsection;

FIG. 8 is a schematic elevation of a blend opener of the fiber blendingsection;

FIG. 9 is a schematic elevation of a separator of the blending section;

FIG. 10 is a schematic elevation of a fine opener of the blendingsection;

FIG. 11 is a side elevation of a feed chute of the fiber collection andfeed section;

FIG. 12 is an enlarged view showing feed and beater rolls of the feedchute of FIG. 11;

FIG. 13 is a side elevation of apparatus in the fiber forming section ofthe invention;

FIG. 14 is an enlarged view of portions of FIG. 13 showing individualfibers being “air laid” onto a moving conveyor;

FIG. 15 is a left end elevational view of FIG. 13;

FIG. 16 is a schematic view showing a fiber forming section, pad makingsection, pad folding section and pad packaging section of the invention;

FIG. 17 is a side elevation showing a web of blended fibers beingcompressed by pressure rolls;

FIG. 18 is a schematic elevation of apparatus in the pad making section;

FIG. 19 is a schematic view showing a laminated web passing through asealing nip;

FIG. 20 is a schematic elevation of a knife roll at a first cuttingstation in the pad making section;

FIG. 21 is a partial sectional view showing the construction of theknife roll of FIG. 20;

FIG. 22 is a schematic view showing a blended-fiber web passing througha nip between the knife roll and a first transfer cylinder;

FIG. 23 is a partial sectional view showing a compressible insert in acutting blade on the knife roll of FIG. 21;

FIG. 24 is an elevation of a first transfer cylinder, with portionsbeing broken away to show a vacuum box inside the cylinder;

FIG. 25 is a section taken on line 25—25 of FIG. 24;

FIG. 26 is a elevation of a sealing roll in the pad making section;

FIG. 27 is a partial sectional view showing the construction of thesealing roll of FIG. 26;

FIG. 28 is an elevation of a knife roll of a second cutting section inthe pad making section;

FIG. 29 is an elevation of apparatus of the folding section andpackaging section;

FIG. 30 is a perspective of apparatus of the folding section;

FIG. 31 is an elevation showing hold-down and folding disks of thefolding section;

FIG. 32 is a an enlarged vertical section taken on line 32—32 of FIG.29, showing a pad folded by the folding disks;

FIG. 33 is an elevation of an adhesive applicator in the foldingsection;

FIG. 34 is a perspective of a conveyor for transporting pads from thefolding section to the packaging section;

FIG. 35 is a perspective of apparatus of the packaging section;

FIG. 36 is a perspective of a forming device for forming a web ofmaterial into a tube around pads delivered to the device;

FIG. 37 is a top plan of the forming device;

FIG. 38 is a side elevation of the forming device and associatedcomponents;

FIG. 38A is a side elevation of an alternate embodiment of the formingdevice and associated components;

FIG. 38B is a perspective of a hold down plate for applying a downwardforce on pads as they move across the forming device;

FIG. 38C is an exploded perspective of the hold down plate of FIG. 38Billustrating air holes in the hold down plate;

FIG. 39 is a vertical section taken on line 39—39 of FIG. 38;

FIG. 40 is a vertical section taken on line 40—40 of FIG. 38;

FIG. 41 is a perspective of an endless belt for applying a downwardforce on pads as they move across the forming device;

FIG. 42 is a perspective of an applicator for applying adhesive to theweb as it moves over the forming device;

FIG. 43 is a front elevation of the applicator of FIG. 42;

FIG. 44 is a horizontal section on line 44—44 of FIG. 43;

FIG. 45 is a perspective of a conveyor for conveying wrapped pads fromthe forming device to the sealing rolls, the conveyor being shown in araised position;

FIG. 46 is a schematic plan view of a series of pads wrapped in atubular wrapper; and

FIG. 47 is a perspective of a sealing roll.

Corresponding reference numbers and characters indicate correspondingparts throughout the drawings.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, an interlabial pad manufactured inaccordance with methods and apparatus of the invention is indicated inits entirety by the reference number 1. In the illustrated embodiment,the pad is generally oval in shape and has lateral projections 3. Thepad may be manufactured in different sizes to fit different users. Forexample, in one size the pad has an overall length along a major axis A1of about 3.1 in. and an overall width along a minor axis A2 of about 2.7in. In another size the pad has an overall length along a major axis A1of about 4.3 in. and an overall width along a minor axis A2 of about 2.7in. As those skilled in the art will understand, the pad may bemanufactured in other sizes and shapes without departing from the scopeof this invention.

In general, the pad comprises an absorbent layer or “core” 5 laminatedbetween first and second outer layers 7 and 9. The absorbent layer ispreferably a blend of fibers, at least one of which is absorbent. By wayof example, the fibers may comprise a blend of cotton fibers providingthe requisite absorbency and rayon fibers providing resilience to thepad, with the cotton/rayon blend ratio preferably ranging from 90/10 toabout 50/50, more preferably 80/20 to 55/45, and still more preferablyabout 60/40. Other fibers and blend ratios can also be used.Superabsorbent materials may also be included, as will be understood bythose skilled in this field. The thickness of the absorbent layer willalso vary, but preferably is in the range of from about 0.025 in. toabout 1.5 in., and more preferably from about 0.05 in. to about 0.5 in.,and even more preferably about 0.08 in. (approximately 2 mm. for lowcapacity interlabial pads).

The first outer layer 7 (sometimes referred to as the “cover” orbody-side layer since it faces the body when the pad is in use) is afluid-pervious layer which may comprise a suitable polymer, such aspolypropylene BCW, having a basis weight of 22 g/m². The second outerlayer (sometimes referred to as a “baffle” layer) may comprisepolyethylene film, for example, having a thickness of 0.75–1.0 mil. Padshaving other laminated configurations, including those where the bafflelayer is fluid-pervious, are also contemplated. In any event, thelamination is sealed around the periphery of the pad, as indicated at11.

FIGS. 3 and 4 illustrate the pad in a folded condition in which the padis folded along its major axis A1 to a position in which opposite sidesections 1A, 1B of the pad face one another, with the cover (body-side)layer 7 facing out for contact with the body when the pad is insertedfor use. In one embodiment, the pad is maintained in this foldedcondition by one or more adhesive spots 15 on the cover (baffle) layer9. As thus folded, the lateral projections 3 on the pad combine to forman area which can be conveniently gripped by the user of the pad toinsert it into proper position in the body.

FIG. 5 illustrates various stages in an overall process for thecommercial manufacture of absorbent articles of laminated construction,including the interlabial pads 1 described above. This process includesa fiber blending section 21 which blends raw fibers (e.g., cotton andrayon fibers), and a fiber collection and feed section 25 for collectinga supply of blended fibers and feeding them to a fiber forming section27 where the fibers are formed into a relatively narrow continuous webused to make the fluid-absorbent layers of the final product (e.g.,interlabial pad 1). The process also includes a pad-making section 31which combines the absorbent layer with the fluid-pervious (cover) layer7 and, if used, the baffle layer 9 to make individual pads. The processalso includes a folding section 33 which includes apparatus for foldingthe pads delivered from the pad-making section 31, and a pad packagingsection 35 in which the folded pads are individually wrapped and,optionally, collated into groups and placed in cartons or other suitablebulk packaging. Each of these stages of the process are described indetail below.

FIG. 6 is a flow diagram illustrating one embodiment of the fiberblending section 21. In this particular embodiment, the section 21comprises first weighing apparatus 41 operable to weigh out anddischarge quantities of a first fiber (e.g., cotton) and second weighingapparatus 43 operable to weigh out and discharge quantities of a secondfiber (e.g., rayon). The weighed and discharged quantities are conveyedto a blend opener, generally designated 47, where the fibers areseparated (“opened”), mixed and then carried away from the blend openerby an air duct 49 of a pneumatic conveyor system. The pneumatic conveyorsystem includes an air separator 51 which separates the longer fibersfrom the air stream and delivers them to a fine opener 55. The shorterfibers (“fiber fines”) are delivered to a fines collector, such as a bagfilter 57. The fine opener 55 further opens and mixes the fibers forconveyance through an air duct 61 to the fiber collection section 25 ofthe system. Each one of these components of the blending section isdescribed in more detail below.

For purposes of the description, the apparatus of the invention has amachine-direction MD which extends generally in the direction of motionof the machine, a lateral cross-direction CD which extends transverselyto the machine direction, and a z-direction Z. As used herein, themachine-direction MD is the direction along which a particular componentor material is transported lengthwise along and through a particular,local position of the apparatus. The cross-direction CD lies generallywithin the plane of the material being transported through the process,and is transverse to the local machine-direction MD. The z-direction Zis aligned substantially perpendicular to both the machine-direction MDand the cross-direction CD, and extends generally along a depth-wise,thickness dimension of the material.

The first weighing apparatus 41 is operable to deliver successiveweighed-out quantities of first fibers, such as cotton fibers. Theparticular unit shown in FIG. 7 is a M-6 “Syncro-Feeder” weigh panfeeder sold by Fiber Controls® Corporation of Gastonia, N.C. Theapparatus comprises a hopper 65 for holding a supply of raw fibers, anda conveyor 67 in the hopper for delivering clumps of fibers from thesupply to a weigher housing 69 containing a feed conveyor 71 forreceiving fibers from the hopper conveyor 67 and conveying them to aninclined lift conveyor 73 having pins or spikes thereon which pickfibers off the feed conveyor 71 and convey them to a weigher comprisinga weigh hopper 77 at the outlet of the unit. An oscillating comb 79adjacent to the upper end of the inclined conveyor 73 combs the fiberson the conveyor and separates (“opens”) them to prevent large clumps offiber from entering the weigh hopper 77. Fibers separated by the combare carried to the top of the inclined conveyor 73 and discharged ontoone or more rotating doffer bars 81 which effect a more uniformdistribution of the fibers into the weigh hopper. Excess fibers combedout by the comb 79 fall back onto the feed conveyor 71 for recycling.The degree of fiber separation can be controlled by adjusting the speedof the inclined conveyor 73 and/or the spacing between the comb 79 andthe inclined conveyor.

The weigh hopper 77 is equipped with a suitable device 83 for measuringthe weight of fibers in the hopper. When a quantity of fibers having apredetermined weight is received in the hopper (e.g., 1120 grams ofcotton fibers), a door 85 above the hopper closes to prevent furtherfibers from entering the weigher until after it has unloaded. When thedoor is closed, fibers delivered from the conveyor 73 accumulatetemporarily in a holding chamber 87 above the weigh hopper 77. At theappropriate time, the weigh hopper opens to deliver a quantity of fibersof predetermined weight onto a conveyor 91 (e.g., an endless beltconveyor) positioned below, after which the door 85 above the weigheropens to admit more fibers into the weigh hopper to repeat the cycle.

The second weighing apparatus 43 is essentially identical to the firstweighing apparatus 41 and is operated to discharge successiveweighed-out quantities of second fibers. Each of these quantities (e.g.,480 grams of rayon fibers) is combined with a weighed-out quantity ofthe first fibers. This may be accomplished in a variety of manners, asby dumping a quantity of second fibers directly on a pile of firstfibers as the latter pile is conveyed beneath the weigher of the secondunit. The combined quantities are then conveyed by the conveyor 91 (FIG.6) to the blend opener.

Referring to FIG. 8, the blend opener 47 may be of the type sold asModel B1X24/30 Opening Blender” from Fiber Controls® Corporation ofGastonia, N.C. As shown, the machine comprises a housing 97 having aninlet in one wall receiving the discharge end of the conveyor 91 fromthe weighers 41, 43, and an outlet in its top wall connected to the airduct 49 of the pneumatic conveyor system which generates a high-velocitystream of air flow through the duct in a direction away from the outlet.Mounted in the housing 97 immediately above the discharge end of theconveyor 91 is a feed roll 101 which is driven to match the speed of theconveyor 91. The feed roll 101 is formed with a series of axial ridgesor flutes 103 along its outer surface and is preferably spring biased ina downward direction against a stop (not shown) to a position in whichit is spaced a predetermined distance (e.g., 3 in.) from the upper reachof the conveyor belt 91. The function of the feed roll 101 is to spreadthe fibers as a layer across the width of the conveyor 91, and to pressthe fibers down against the conveyor for a controlled feed of the fibersforward at a relatively slow speed (e.g., 9 fpm). At this point in theprocess, the fibers making up the layer on the conveyor 91 arerelatively stratified, with the fiber dumped first on the conveyor(e.g., cotton) being on the bottom and the fiber dumped second being ontop. The feed roll 101 and conveyor 91 are preferably driven at the samespeed by a common drive the speed of which is adjustable as needed.

A large cylindric beater roll 105 having an axial dimension generallycorresponding to the full width of the conveyor 91 (e.g., 24 in.) ismounted for rotation in the housing 97 upstream from the conveyor 91 andfeed roll 101. A multiplicity of pins or teeth 107 are mounted on theouter surface of the roll, each pin being threaded in a mounting block109 secured to the roll. Preferably, the pins 107 are arranged in anumber of parallel rows extending along the outer surface of the roll inan axial direction. (For example, a beater roll having a diameter of 24in. may have 12 rows of pins mounted at equal angular intervals aroundthe roll.) A cut-off blade 111 is mounted adjacent the outlet of thehousing and extends the full axial length of the roll closely adjacentthe tips of the pins (e.g., the clearance may be about 0.02 to 0.05in.).

The beater roll 105 is rotated at relatively high speed (e.g., about 750rpm) by a suitable motor and drive train (not shown). Fibers fed towardthe roll 105 by the conveyor 91 and feed roll 101 are pulled and combedat high speed by the pins 107 and carried to the outlet of the housing97 where they are drawn into the air duct 49 and entrained in the airstream generated by the pneumatic conveyor system. The cut-off blade 111assists in the removal of fibers from the roll 105. The high-speedpulling and combing action on the fibers, combined with the pneumaticconveyance of the fibers from the outlet of the machine, furtherseparates (“open”) and mixes the fibers, as will be understood by thoseskilled in this field.

The air duct 49 conveys the fibers from the blend opener 47 to the airseparator 51 by means of a high-speed air stream generated by a firsttransfer fan 115 located downstream from the separator (see FIG. 6). Inone embodiment, for example, the air moves at a velocity in the range of2500–4000 FPM and at a flow rate of 1300–3500 CFM. As shown in FIG. 9,the air separator 51 in the preferred embodiment comprises a housing 121having an inlet section 123 with an inlet 125 for receiving airbornefibers from the blend opener 47 and an outlet section 127. The outletsection 127 has an upstream air outlet 131 for the exit of air from theseparator and a downstream fiber outlet 133 for exit of fibers from theseparator into the fine opener 55.

The inlet and outlet sections 123, 127 of the housing 121 are configuredto direct the air stream entering the inlet along a path 137 which turnsa corner, e.g., a 90° corner at the junction of the inlet and outletsections in a preferred embodiment. As a result of this change indirection, many of the heavier fibers are moved by centrifugal forcetoward the outside of the turn and continue on to the fiber outlet 133.A rotary air lock 144 at the fiber outlet 133 substantially inhibits theflow of air through the outlet while allowing for the passage of suchfibers, thus “separating” the fibers from the air. Similar to arevolving door, the air lock 144 comprises a central hub 145 and aplurality of sealing arms 147 extending radially out from the hub whichwipe against a wall 151 defining the outlet 133 to substantially sealagainst the passage of air. In the preferred embodiment, the air lock144 is motor driven at a speed which may be varied to meet the fiberfeed requirements of the system. As the air lock rotates, it sweepsfibers deposited between the arms 147 through the outlet 133.

Because the flow of air through the fiber outlet 133 is substantiallyblocked by the rotary air lock 144, essentially all of the air enteringpneumatic distributor 51 exits through the air outlet 131. A screen 155is mounted in the housing 121 adjacent this air outlet 131 to catch thelarger fibers while permitting small fibers or “fines” to pass throughthe air outlet to an air duct 157 which leads to the fines collector 57,which may be of any suitable construction, such as a Model AF-2 bagfilter sold by Fiber Controls® Corporation of Gastonia, N.C. The meshsize of the screen 155 can vary, depending on the desiredcharacteristics of the final product, but preferably the openings in thescreen have a maximum dimension of about 0.125 in. Fibers collected onthe screen are removed by a rotatable blade 161 mounted in the housing121. The blade carries the fibers away from screen and delivers themback to the air stream for transport to the fiber outlet 133.

A damper 165 in the air duct 157 connected to the fines collector 57 ismovable between an open position, as shown, for permitting air flowthrough the air outlet 131 to the collector, and a closed position forblocking the flow of air through the air outlet. It will be noted inthis regard that if the pneumatic conveyor system comprises multiple airseparators and associated equipment, there may be occasions where aparticular unit(s) is not needed, in which case the damper 165 can beclosed to block the flow of air through that particular separator. Thefirst transfer fan 115 is mounted in the air duct 157 between the airseparator 51 and the fines collector 57.

FIG. 10 illustrates one embodiment of the fine opener 55, which is soldas Model VFO 36 from Fiber Controls® Corporation of Gastonia, N.C. Thefine opener comprises a housing 171 having an inlet 173 connected to thefiber outlet 133 of the air separator 51, and an outlet 175 connected byair duct 61 to the fiber collection and feed section 25, a secondtransfer fan 179 being mounted in this air duct 61 to generate an airstream for transporting fibers from the fine opener 55 to the fibercollection and feed section 25.

A plurality of fluted nip rolls (e.g., three such rolls 181, 183, 185are shown in FIG. 10) are mounted in the housing 171 immediatelydownstream from the inlet 173 and rotate to transport fibers enteringthe fine opener 55 along a path between a pair of closely spaced feedrolls 187, also having fluted surfaces. (The flutes on the nip rolls181, 183, 185 are typically relatively narrow, resembling blades or finsextending the full length of each roll at spaced circumferentialintervals around the roll, while the flutes on the feed rolls 187 arepreferably somewhat wider, resembling gear teeth with flat tops.) Thefeed rolls 187 feed the fibers to a clothing cylinder 191 which rotatesin the housing 171 at high speed, e.g., 1000 rpm. Suitable card clothing193 (e.g., teeth or hooks) is mounted on the clothing roll 191 along acontinuous spiral path from one end of the cylinder to the other, aswill be understood by those skilled in this art. The nip and feed rollsare preferably driven by a common DC motor 197, the output of which isadjustable to vary the speed of these rolls, as needed. The clothingroll 191 is preferably driven by an AC motor (not shown) for rotation ofthe roll at a constant speed.

As the clothing roll 191 rotates at high speed past the feed rolls 187,the clothing on the roll functions to further open the fibers and totransport them to the outlet 175 of the machine, where the fibers aredrawn up and through the outlet. A cut-off blade 201 mounted adjacentthe outlet has an edge positioned closely adjacent the roll 191 forsubstantially preventing fibers from being carried by the clothing rollpast the outlet 175. A similar blade 205 is mounted with its tip endadjacent the upper feed roll 187 for preventing build-up of fibers onthe feed roll. Air flows into the housing 171 through an air inlet 207.

A fiber-level sensor (e.g., photocell), not shown, is mounted in thehousing 171 of the fine opener 55 for controlling the level of fiberdelivered to the inlet 173. In the event the fibers back up to a levelconsidered excessive, the sensor is operable to signal the upstreamweighing apparatus 41, 43 and blend opener 47 to stop further deliveryof fibers until the level of fibers drops below a predetermined level(e.g. the level of the sensor), after which the upstream equipment issignaled to resume operation. Other sensing devices operating indifferent manners may be used.

FIGS. 11 and 12 illustrate apparatus at the fiber collection and feedsection 25 of the system downstream from the fine opener 55. Thisapparatus comprises, in one embodiment, a feed chute, generallydesignated 221. The feed chute collects (accumulates) a supply ofblended fibers and feeds the fibers as an initial layer or mat ofblended fibers to the fiber forming section 27. More specifically, thefeed chute 221 comprises a housing 223 having an inlet 225 connected tothe air duct 61 for receiving fibers from the fine opener 55, and anoutlet 227 through which a continuous supply of blended fibers isdischarged to the forming section. The particular feed chute 221 shownin this embodiment is a Model FCF-40 chute feeder sold byPlatt-Saco-Lowell, formerly of Greenville, S.C.

The housing has an upper section 229 which includes an upper chute 231for holding a supply of fibers delivered through the inlet 225, and alower section 233. One wall 237 of the upper chute 231 is perforated(e.g., the wall may be a screen of fine mesh) to permit the escape ofincoming air from the chute. The level of fiber in the upper chute 231is controlled by suitable means, such as a pressure switch 241 adjacentthe inlet operable to signal a shutoff of the upstream equipment (e.g.,weighing apparatus 41, 43, blend opener 47 and fine opener 55) in theevent the air pressure in the upper housing section 229 exceeds apredetermined pressure, indicating that the upper chute 231 is full, andto signal activation of the upstream equipment when the pressure fallsbelow a predetermined pressure, indicating that the supply of fiber inthe upper chute has fallen to a level requiring replenishment.

A feed roll 245 is rotatably mounted in the lower section 233 of thehousing immediately below the upper chute 231 to feed fibers from theupper chute 231 to a beater roll 247. The fiber is fed past the feedroll 245 through a gap 251 (FIG. 12) defined by a guide surface 255spaced from the feed roll 245 a suitable distance (e.g., about 0.25in.). The feed roll 245 is preferably equipped with card clothing (notshown) similar to the clothing cylinder of the fine opener 55, and thebeater roll 247 has a construction similar to the beater roll 105 in theblend opener 47, although it is preferably somewhat smaller (e.g., adiameter of 10.5 in. with twelve rows of pins or teeth). The feed roll245 is preferably rotated by a variable speed motor (not shown) to feedthe fiber to the beater roll 247 at the desired rate. The beater roll247 is preferably rotated at a suitable speed (e.g., 1800 rpm) by aconstant speed motor to feed the blended fibers into the lower section233 of the feed chute and to perform an additional opening step on thefibers. Fibers on the beater roll 247 are directed by an adjacent guidewall 261 in the housing to the upper end of a fiber accumulation chute263 in the lower section 233 of the housing 223.

Referring to FIG. 11, the lower accumulation chute 263 is defined, in apreferred embodiment, by vertical walls, one of which comprises a shakerplate 267 pivoted at its upper end for back-and-forth oscillation bymeans of a shaker arm assembly generally designated 271 adjacent thelower end of the plate. The shaker arm assembly 271 comprises one ormore shaker arms 273 each of which has an inner end connected to a wheel275 at an off-center location, and an outer end connected (as by aclevis 277) to the shaker plate 267, the arrangement being such thatrotation of the wheel causes the shaker arm and the shaker plate tooscillate back and forth. This movement prevents the bridging of fibersin the lower chute 263 and facilitates the uniform feed and packing offiber in the chute to provide a supply of blended fibers, e.g., a columnof substantially uniform density or “basis weight” (typically measuredin grams/square meter). The length of the shaker arm 273 is adjustableby means of a turnbuckle 281 or the like, so that the amplitude of theoscillating movement can be varied, as needed. The shaker arm wheel 275(or wheels) is preferably driven at the desired speed by a variablespeed DC motor (not shown). Other means may be used instead of theshaker plate and shaker arm assembly 271 for facilitating the flow andpacking of fibers in the lower chute 263.

The level of fibers in the lower accumulation chute 263 is controlled bysuitable means, such as a pair of upper and lower sensors, e.g., upperand lower photo cells indicated at 285 and 287, respectively, in FIG.11. The upper photo cell 285 is operable to signal a shutoff of theupstream equipment (e.g., weigh apparatus 41, 43, blend opener 47 andfine opener 55) in the event the height of the column of fibers in thelower chute 263 exceeds a predetermined height, indicating that thelower chute is full. The lower photo cell 287 is operable to signalactivation of the upstream equipment when the height of the column fallsbelow a predetermined level, indicating that the need for additionalfibers. The upper and lower sensors 285, 287 are preferably closelyspaced for maintaining the height of the fiber column relativelyconstant so that the density of fibers discharged from the chute issubstantially uniform.

Fibers in the lower chute 263 are fed through the outlet 227 by feedmeans comprising, in one embodiment, a pair of compression rolls 291defining a compression nip 293 immediately adjacent the outlet of thehousing. These compression rolls 291 preferably function to compress thefibers into a continuous mat or layer 295 of blended fibers which isdischarged through the outlet 227 for delivery to the fiber formingsection 27 of the system.

FIGS. 13–15 illustrate one embodiment of the forming section 27 of thesystem of the invention. In this section, the layer 295 of fiberdelivered from the outlet 227 of the feed chute 221 is broken up andreformed as a preferably (but not necessarily) narrower layer having awidth generally corresponding to the width of the absorbent layer of thefinal product (e.g., layer 5 of pad 1). In general, the fiber formingsection 27 of this particular embodiment comprises a transfer device 301for feeding the layer of fiber from the outlet 227 of the feed chute toa fiberizing station 303 at the downstream end of the transfer device.In the preferred embodiment, the transfer device is a slide (alsodesignated 301) down which the layer gravitates. Alternatively, thetransfer device could be an endless conveyor or other device.

Apparatus generally designated 311 is provided at the fiberizing station303 for breaking up the incoming layer 295 into individual fibers, aprocess which may be referred to as “fiberizing”. As illustrated, thisfiberizing apparatus 311 comprises a feed mechanism including a feedroll 315 spaced from a guide surface 317 (FIG. 14) to form a gap 319through which the layer 295 of fibers is fed to a fiberizing mechanismcomprising, in one embodiment, a roll 321 having teeth, e.g., a lickerinroll, mounted immediately adjacent the gap. Alternatively, a rotaryhammer mill or other device may be used.

The feed roll 315 is carried by a pair of levers 325 (only one shown inFIG. 14), each of which has a pivot connection 327 with the machineframe for adjusting the size of the gap 319. Preferably, the gap is setto be less than the thickness of the incoming layer 295 (e.g., 0.012 in.compared to about 2.5 in.) so that the layer of fibers is compressed andfed forward to the fiberizing roll 321 at a controlled rate of speed(e.g., 6 fpm). The feed roll 315 is preferably driven by a variablespeed DC motor 329 (FIG. 13). The fiberizing roll 321 preferably rotatesin a direction opposite the rotational direction of the feed roll 315,and the teeth on the roll 321 function to break up or “fiberize” thelayer 295 into small tufts and individual fibers. The fiberizing roll ispreferably driven by an AC motor 333 at a constant, relatively highspeed (e.g., 1800 to 2400 rpm).

The fiber forming section 27 also includes a conveyor 335 (FIG. 15)having foraminous forming surface 337 positioned below the fiberizingroll 321 and preferably running in a direction generally transverse(e.g., at right angles) to the direction of feed to the fiberizing roll,and fiber-directing apparatus, generally designated 341, for directingfibers from the fiberizing roll to the surface 337 on which they arereconstituted as a “reformed” layer 343 (FIG. 14) on the conveyor 335,hereinafter referred to as the “reforming” conveyor. In one embodiment,the forming surface 337 of the reforming conveyor 335 comprises anendless belt made of wire mesh or screen, the openings beingappropriately sized for the forming (e.g., 11% open area). The formingsurface 337 is preferably substantially narrower than the width of thelayer 295 fed to the fiberizing roll 321 (e.g., 3 in. versus 40 in.)and, in one embodiment, extends generally parallel to the axis ofrotation of the fiberizing roll.

It will be understood that a fiberizing mechanism other than a roll withteeth (e.g., lickerin roll 321) could be used without departing from thescope of this invention. Any mechanism (e.g., a rotary hammer mill) canbe used, provided it is capable of breaking up the layer 295 intoseparate fibers for reformation on the reforming conveyor 337 insubstantially random orientation.

Referring to FIGS. 14 and 15, the fiber-directing apparatus 341comprises, in the preferred embodiment, an air chamber 347 positionedbetween the fiberizing roll 321 and the reforming conveyor 335. The airchamber 347 has an upper inlet end located adjacent the fiberizing roll321 and a lower outlet end located immediately above the forming surface337 of the conveyor 335, although the air chamber could haveorientations other than vertical without departing from the scope ofthis invention.

As viewed in FIG. 15 in which the reforming conveyor 335 transportsfibers from right to left, the upper end of the air chamber has a lengthgenerally corresponding to the axial length of the fiberizing roll 321which, in turn, is preferably at least as wide as the layer 295delivered from the feed chute 221. Referring to FIG. 14, the air chamber347 has a front (left) wall defined at least in part in one embodimentby a door 351 pivoted at its upper end at 353 so that the door may beswung up and down between open and closed positions, a rear wall 355,and opposite side walls 357 (FIG. 15). The air chamber 347 has a width(i.e., the distance between the front and back walls 351, 355 of thechamber) at its lower end generally corresponding to the width of thereformed layer 343 of fibers formed on the reforming conveyor 335. Theforming surface 337 of the conveyor 335 is positioned over an elongateair manifold 361 which communicates with a vacuum fan (not shown) bymeans of air duct 363. The arrangement is such that operation of the fangenerates an air stream down through the air chamber 347 and through theforming surface 337 to “air lay” a layer of fibers on the formingsurface. Air is provided to the air chamber 347 via an airway 367 (FIG.14) adjacent the juncture of the fiberizing roll 321 and the upper inletend of the air chamber.

The airway has a throat 371 which is adjustable in size to regulate theflow of air to the air chamber, adjustment being effected by means suchas a movable sabre bar 373 or other suitable device. Seals are providedto prevent the drawing of air into the air chamber 347, includingsealing strips 375 along the sides of the door, the top edge of thedoor, and strips along the bottom edges of the door and rear wall (FIG.14). The vacuum fan should be sized to generate a relatively high-speedstream of air through the air chamber 347 sufficient to direct fibersfrom the fiberizing roll 321 onto the reforming conveyor 335 to form alayer of blended fiber of suitable thickness and density.

The reformed layer 343 may be formed on a conveyor other than an endlessbelt. For example, the reformed layer could be deposited or “air laid”on a rotatable vacuum drum of the type well known in the art forproducing air formed fibrous webs.

The breaking up or disintegration of the layer 295 of fibers by thefiberizing roll 321 and deposit of the fibers as a reformed layer 343 onthe reforming conveyor 335 tends to randomize the orientation of thefibers, resulting in good tensional strength of the final product in alldirections and more uniform wicking and distribution of bodily fluid inall directions away from the location of impingement on the fibers.Further, reforming the layer 295 at an angle (e.g., 90°) which istransverse to the machine direction MD of feed to the fiberizer 321tends to average any cross sectional variations in the layer.

As best illustrated in FIG. 15, the reforming conveyor 335 is driven bya drive roll 381 powered by a suitable motor to drive the conveyor at aspeed substantially faster than the speed at which the initial layer 295of fiber is delivered from the feed chute 221 to the fiberizing roll321. Preferably, the width of the initial layer 295 delivered from thefeed chute is at least 5 times greater than the width of the reformedlayer 343 on the reforming conveyor 335, and the reforming conveyorpreferably runs at a speed at least 10 times greater than the speed atwhich the initial layer is fed to the fiberizing roll.

By way of example, the initial layer may have a width of about 40 in.and a thickness of about 2.5–3.0 in., and the speed at which the initiallayer is fed to the fiberizing roll may be 5–8 fpm. On the other hand,the reformed layer may have a width of about 3 in. and a height of about0.5 in., and the reforming conveyor 335 may run at a speed of 370 fpm.The speed of the reforming conveyor is preferably adjustable. Fiber dustis removed from the reforming conveyor by a cleaner 385 mounted at alocation upstream from a belt drive roll. In one embodiment, the cleanercomprises an air jet which is operable to blow fibers off the conveyorand a vacuum pick-up (not shown) opposite the air jet. Other cleaningmechanisms may be used. The endless belt of the conveyor 335 ismaintained under tension by a conventional tensioning device indicatedat 389.

The door 351 at the front of the air chamber 347 may be opened to accessthe reforming conveyor 537 and associated equipment. During normaloperation, however, the door 351 is held in its closed position by apair of locking pins 393. An additional security system, generallydesignated 395 in FIG. 14, may also be provided to lock the door closed.

After the fibers are reformed on the reforming conveyor 335 as apreferably narrower layer, the reformed layer 343 is compressed to afinal thickness. Preferably, compression occurs in two stages. In afirst stage, the reformed layer is lightly compressed by a compressionconveyor 401 positioned above the reforming conveyor 335 downstream fromthe air chamber 347 (FIGS. 15–17). The compression conveyor 401 ispreferably an endless belt having a lower reach spaced from the formingsurface 337 of the reforming conveyor 335 by a distance sufficient tolightly compress the incoming layer 343 of fibers. The vertical positionof the compression conveyor 401 is preferably adjustable to vary thesize of the gap between the two belts and thus the magnitude of thecompressive forces applied to the layer, as needed.

In the second stage, the layer 343 is more severely compressed by ade-bulking module, generally designated 405 in FIG. 17. In oneembodiment, this module 405 comprises a pair of pressure rolls havinghardened surfaces, the lower pressure roll 407 being mounted in fixedposition and the upper roll 409 being vertically movable relative to thelower roll, as permitted by a power cylinder 411 mounted above the upperroll. The power cylinder exerts a downward force (e.g., 2400 lbs) onbearing blocks 415 at the ends of the upper roll to hold the blocks downagainst fixed stops (not shown) which maintain a gap of predeterminedsize between the pressure rolls unless the compressive force exerted bythe rolls 407, 409 on the layer 343 exceeds a predetermined force, inwhich event the upper roll 409 will yield in an upward direction. Thesize of the gap at the nip of the rolls 407, 409 can be adjusted bychanging the position of the fixed stops. The compressive force exertedby the pressure rolls is preferably sufficient to compress the layer 343to a final thickness (e.g., 0.08 in. for an interlabial pad) which issubstantially the same as the thickness of the absorbent layer of thefinal product (e.g., layer 5 of pad 1). As thus compressed, the layer343 is conveyed, preferably as a continuous integral web 417 (FIG. 17)of blended fibers, by one or more conveyors 421 to the pad-makingsection 31.

Referring to FIGS. 16–19, the pad-making section 31 comprises, ingeneral, first and second unwind rolls 425, 427 on which are wound webs7W, 9W of material corresponding to the cover and baffle layers 7, 9 ofthe final pad 1, and a first cutting station 431 at which the web 417 ofblended fibers is cut to form individual absorbent bodies in the web(e.g., cores 5 for pads 1). Section 31 also includes a web sealingstation 435 at which the cover and baffle webs 7W, 9W are applied toopposite faces of the bodies 5 to form a laminated web 437 (FIG. 19)which is sealed around the bodies 5, and a second cutting station 441 atwhich the laminated web 437 is cut around the pads prior to transport ofthe pads to the folding section 31. Each of these components isdescribed in detail below.

A conveyor (e.g., an endless belt conveyor 447 including a belttensioning device 449) receives the blended-fiber web 417 at the entryend of the pad-making section, which is the left end as viewed in FIG.18, and conveys the web 417 to the first cutting station 431. Cuttingapparatus is provided at this station comprising, in one embodiment,opposing cutting rolls 451, 453 which define a first cutting nip CN1.One of these rolls (451) is a knife (die) roll and the other (453) is ananvil roll. In this embodiment, the knife roll 451 is mounted in fixedvertical position below the anvil roll 453 but this orientation may bereversed. The knife roll 451 has a series of cutting dies (blades) 457(FIG. 20) mounted on the roll in a pattern corresponding to the patternof absorbent bodies (e.g., cores 5) to be cut in the web. The anvil roll453 has a hardened, polished metal surface and is preferably positionedso that the gap between the rolls at the first cutting nip CN1 issufficiently small (e.g., 0.0005 in.) to enable the cutting blades 457to cut substantially completely through the blended-fiber web 417.

The anvil roll 453 is preferably vertically movable relative to theknife roll 451 in the same manner as described above in regard to theupper pressure roll 409, a power cylinder 461 being provided for thispurpose. The cylinder exerts a downward force on bearing blocks of theanvil roll 453 to hold the blocks down against fixed stops (not shown)and thus maintain the size of the gap (if any) at the first cutting nipCN1 unless the compressive force exerted by the rolls 451, 453 on theweb 417 exceeds a predetermined force, in which event the upper rollwill yield in an upward direction. The size of the gap can be adjustedby changing the position of the fixed stops, as will be understood bythose skilled in this field.

After the web 417 has been cut to form the absorbent bodies (e.g., cores5), it is desirable to maintain the bodies in precise position as theyare transported through the pad-making section 31, so that the variouscomponents of the final pads (e.g., pads 1) are in substantially preciseregistration. To this end, the knife roll 451 is a vacuum rollcomprising a cylindric body 465 (see FIGS. 20–22) formed with vacuumpassages including, in one embodiment, axial passages 467 running fromthe ends of the body along the length of the body and radial passages469 extending from the axial passages 467 radially outward to formvacuum openings 471 (FIG. 20) in the outer surface of the body. Vacuumboxes 475 are mounted at opposite ends of the body 465, each box beingopen adjacent a respective end face of the body. The vacuum boxes 475communicate by means of air ducts 479 with a vacuum system comprising atleast one vacuum fan (not shown) for generating a negative pressure inthe vacuum boxes to draw air through the passages 467, 469 in the body.Seals 483 around the opening in each vacuum box 475 are positioned closeto the respective end faces of the rotating cylindric body 465 to sealagainst leakage of air from the box.

In the embodiment shown in FIGS. 18 and 20, the vacuum boxes 475 extendover about a 90° arcuate segment along the upper part of the knife roll451 from about the 12:00 position adjacent the first cutting nip CN1 toabout a 3:00 position for transfer of the absorbent bodies to a firsttransfer cylinder 485, the transfer occurring at a first transfer nipTN1 defined by the knife roll 451 and transfer cylinder 485. The vacuumopenings 471 in the outer surface of the knife roll 451 are so arrangedand located that the absorbent bodies cut from the web are vacuumgripped and held in precise position on the knife roll as it rotates ina clockwise direction from the cutting nip CN1 to the first transfer nipTN1, where the absorbent bodies are transferred to the first transfercylinder 485 rotating in the same direction, as will be described. Scrapmaterial 491 (i.e., trim from the web 417 around the absorbent bodies)is removed from the knife roll during or after the transfer of theabsorbent bodies takes place, as by means of a vacuum duct 493 (see FIG.22). The duct 493 has an inlet adjacent the knife roll 451 andcommunicates with the aforementioned vacuum system to draw the scrapmaterial 491 into the duct for delivery to the inlet section of the feedchute 221 for recycling, or to a suitable waste collector for disposal.

Referring to FIGS. 20 and 21, the body 465 of the knife roll 451 may beof multi-piece construction, comprising a shaft 497 surrounded by asleeve 499 fabricated as a plurality of arcuate segments (e.g., 3 suchsegments 499 A–C are illustrated in FIG. 20) affixed to the shaft bysuitable fasteners 501 (FIG. 21) which extend through bores 503 in thesleeve 499 and are threaded into the shaft 497. In one embodiment, eachsegment 499 A–C carries two cutting dies or blades 457, each having anoutline corresponding to the shape of the absorbent body 5 to be cutfrom the web. An insert 507 (FIG. 23) of a compressible but resilientmaterial is secured to the outer surface of the body 465 of the kniferoll 451 inside the perimeter of the blade 457, as by a suitableadhesive. The insert 507 may be an adhesive-backed body of cross-linkedpolyethylene foam, for example, having a tensile strength of 44 to 55psi and a compression such that the material deflects 25% at a pressureof 12.7 to 15.5 psi. Such a foam is commercially available under thetrademark “Volara” from McMaster-Carr Supply Company of Chicago, Ill. Inits relaxed (uncompressed) condition or state, as shown in FIG. 23, theinsert 507 projects out from the surface of the knife roll 451,preferably a distance slightly less than the height of the cutting blade457. For example, for a cutting blade 457 having an overall height of0.19 in., the insert 507 may project out a distance of 0.125 in. Theinsert 507 is porous (due either to the porous nature of the insertmaterial or to holes 509 made in the insert) to provide for the transferof vacuum from the vacuum openings 471 in the surface of the knife roll451 through the insert. When the web 417 of absorbent material passesthrough the cutting nip CN1, the insert 507 is compressed to permitcutting of the material by the blade 457. After the web passes throughthe cutting nip, the tendency of the insert 507 to expand to its relaxedstate exerts a small outward pushing force on the absorbent body 5 cutby the cutting blade 457. This outward force assists in the cleanseparation of the absorbent body 5 from the web 417 and the transfer ofthe absorbent body to the first transfer cylinder 485 at the firsttransfer nip TN1.

As shown in FIGS. 24 and 25, the first transfer cylinder 485 comprises ahollow body in the form of a drum 515 having a cylindric outer surfaceformed with a pattern of vacuum holes 519 generally corresponding to theshapes of absorbent bodies 5 transferred from the knife roll 451. Avacuum box 521 mounted in fixed position inside the drum 515 has anarcuate surface 525 defining a vacuum opening 527 positioned closelyadjacent the inside wall 529 of the drum. The vacuum box 519communicates by means of one or more air ducts 531 with theaforementioned vacuum system so that a negative pressure is generated inthe vacuum box to draw air through the vacuum holes 519 in the outersurface of the drum as the drum rotates past the box. Seals 533 aroundthe opening 527 in the vacuum box wipe against the inside wall 529 ofthe rotating drum 515 to seal against leakage of air. In the embodimentshown in FIG. 18, the vacuum box extends over more than about a 180°(e.g., about 190°) arcuate segment along the lower half of the drum fromabout the 9:00 position adjacent the first transfer nip TN1 to about a3:00 position for transfer of the absorbent bodies 5 to the web sealingstation 435, as will be described. The vacuum holes 519 in the firsttransfer cylinder 485 are located and arranged such that absorbentbodies 5 transferred to the first transfer cylinder 485 at the firsttransfer nip TN1 are vacuum gripped and held in precise position on thetransfer cylinder as it rotates in a counterclockwise direction from thenip TN1 to about the 3:00 position. An exemplary pattern of vacuum holes519 is illustrated in FIG. 24.

In the embodiment shown in FIG. 18, the web sealing station 435 includessealing apparatus comprising, in one embodiment, a pair of opposingsealing rolls 541, 543 defining a sealing nip SN, one such roll (541)being shown as a lower sealing roll and the other as an upper roll. Theupper sealing roll 543 has a smooth, uninterrupted cylindric surface andis mounted in the same manner as the anvil roll 453 at the first cuttingsection 431, a power cylinder 547 being provided for this purpose. Thelower sealing roll 541 is mounted for rotation in a fixed verticalposition and defines a second transfer nip TN2 with the first transfercylinder 485. The lower sealing roll 541 has a construction similar theknife roll 451, except that the body of the roll has a smooth cylindricouter surface 551 (FIGS. 26 and 27) formed with a pattern of recesses orpockets 553 therein which are sized and shaped for receiving theabsorbent bodies 5 transferred from the first transfer cylinder 485.Each pocket 553 has an outline which is slightly oversize relative tothe outline of an absorbent body 5. The pocket 553 has a depth (i.e., inthe Z direction) slightly greater than the depth of the absorbent body 5so that the absorbent body is not compressed at the sealing nip SN.Alternatively, the depth of the pocket 553 can be made less than thethickness of the absorbent body 5 to provide for some compression of theabsorbent body at the sealing nip, if desired.

The depth of the pocket 553 can be controlled by placing one or moreperforated inserts of predetermined thickness in the pocket. Like theknife roll 451 at the first cutting station 431, the lower sealing roll541 is also formed (e.g., machined) to have a series of axial and radialvacuum passages 557, 559 therein to create vacuum openings 561 in theouter surface 551 of the roll. Also like the knife roll 451, vacuumboxes 565 are mounted adjacent opposite ends of the lower sealing roll541 and are connected by air ducts 567 to the vacuum system forgenerating a vacuum at the vacuum openings 561 on the roll 541. FIG. 26illustrates a pair of exemplary pockets 553 formed in the outer surface551 of the lower sealing roll 541.

In the embodiment shown in FIG. 18, the vacuum boxes 565 at the ends ofthe lower sealing roll 541 extend over more than about a 180° (e.g.,about 190°) arcuate segment along the upper half of the roll from aboutthe 9:00 position adjacent the second transfer nip TN2 to about a 3:00position for transfer of the absorbent bodies 5 and accompanying webs7W, 9W to a downstream second transfer cylinder 571 defining a thirdtransfer nip TN3 with the lower sealing roll 541. In an alternateembodiment, the vacuum boxes 565 at the ends of the lower sealing roll541 extend over an arcuate segment along the upper portion of the rollfrom about the 9:00 position adjacent the second transfer nip TN2 toabout a 12:00 position for transfer of the absorbent bodies 5 andaccompanying webs. As will be more fully described below, the twosealing rolls 541, 543 function to apply the cover and baffle webs 7W,9W from the unwind rolls 425, 427 to the absorbent bodies 5 to form thelaminated web 437, and then to seal the laminated web for delivery tothe third transfer nip TN3.

Apparatus for feeding the cover web 7W for lamination with the absorbentbodies is shown in FIG. 18. This apparatus comprises the unwind supplyroll 425 of cover web 7W material, corresponding to the cover layer 7 ofa final pad (e.g., pad 1), mounted on a shaft 575 driven by a variablespeed motor (not shown). The speed of the motor is controlled so thatthe rate at which web 7W is fed from roll 425 closely matches the rateat which the blended-fiber web 417 is fed to the pad-making section 31.One aspect of this feed control involves a sensing device 581 downstreamfrom the unwind roll 425 for sensing a change in web tension due, forexample, to the decrease in roll diameter as web is fed from the roll,and for signaling the motor to speed up or slow down to maintain asubstantially uniform tension in the web corresponding to the desiredspeed. In one embodiment, the sensing device 581 comprises a dancer bar583 pivoted on the frame of the machine, a dancer roll 585 rotatable onthe bar and in contact with the web 7W, and a potentiometer (not shown)for sensing movement of the bar as a result of changes in web tension.Other sensing devices can be used. The cover web 7W is directed by aseries of idler rolls 589 to the lower sealing roll 541 where it ispulled through the second transfer nip TN2.

As the web is pulled through the nip, absorbent bodies 5 are transferredfrom the first transfer cylinder 485 to the lower sealing roll 541 in aposition overlying the cover web 7W to laminate the absorbent bodies onthe web and thus form a lamination. The cover web 7W is of an air andfluid-pervious material, so that both the web and the absorbent bodiesare subject to the vacuum force applied by the vacuum openings 561 inthe sealing roll 541 to hold the web and bodies in precise position onthe lower sealing roll (see FIG. 19). Further, the pockets 553 in theouter surface 551 of the lower sealing roll 541 are positioned forreceiving the absorbent bodies as they are transferred from the firsttransfer cylinder 485, the end result being that the cover web andabsorbent bodies are held by the vacuum of the lower sealing roll in thepockets and held in this laminated condition for conveyance to thesealing nip SN.

Apparatus for feeding a baffle web 9W for lamination with the cover web7W and absorbent bodies 5 is also shown in FIG. 18. This apparatuscomprises the second unwind supply roll 427 of baffle web material 9W,corresponding to the baffle layer 9 of a final pad (assuming a bafflelayer is included), mounted on a shaft 591 driven by a variable speedmotor (not shown). The operation and control of this motor is similar tothat of the first unwind roll 425 described above and will not berepeated. A web tension sensing device 595 similar to device 581 isprovided downstream from the second unwind roll 427. A series of idlerrolls 599 direct the baffle web 9W past an applicator 601 whichfunctions, in one embodiment, to apply (e.g., spray) a suitable adhesive(e.g., hot-melt adhesive) to a face of the web 9W to be applied to theabsorbent bodies 5 and at locations generally corresponding to theperipheral seal 11 of the final pad, as shown, for example, in FIG. 1.Other types of applicators, adhesives and/or sealing methods may besuitable. Additional idler rolls downstream from the applicator 601direct the baffle web 9W to the sealing nip SN defined by the sealingrolls 541, 543, where the baffle web is applied over the face of eachabsorbent body 5 opposite the cover web 7W, with the adhesive on thebaffle web facing the lower sealing roll.

As the lamination of webs 7W, 9W and absorbent bodies 5 pass through thesealing nip SN (FIG. 19), pressure is applied by the sealing rolls 541,543 to bring the adhesive on the baffle web 9W into pressure contactwith opposing surfaces of the cover web 7W to seal the cover and bafflewebs together around each absorbent body 5. If a hot-melt adhesivesystem is used, the distance between the applicator 601 and the sealingnip SN should be such that, given the speed at which the baffle web 9Wis fed forward, the adhesive is sufficiently heated at the sealing nipto form a proper seal. Alternatively, one or both of the sealing rolls541, 543 may be heated (ultrasonically or otherwise) to form heat sealsaround the absorbent bodies.

In the preferred embodiment of FIGS. 19, 26 and 27, the vacuum openings561 in the lower seal roll 541 vacuum grip the sealed laminated web 537.As the sealing roll rotates, it exerts a pulling force on the web andconveys the web in a clockwise direction from the sealing nip SN toabout a 3:00 position where the web is transferred to the secondtransfer cylinder 571 at the third transfer nip TN3. In one embodiment,the construction of the second transfer cylinder 571 is essentiallyidentical to the construction of the first transfer cylinder 485. In theembodiment shown in FIG. 18, the vacuum box 603 inside the secondtransfer cylinder 571 extends over more than about a 180° (e.g., about190°) arcuate segment along the lower half of the cylinder from aboutthe 9:00 position adjacent the third transfer nip TN3 to about a 3:00position for transfer of the sealed laminated web 537 to the secondcutting station 441. The vacuum openings (not shown) in the secondtransfer cylinder 571 are located and arranged such that the web isvacuum gripped and pulled as the cylinder rotates in a counterclockwisedirection, while maintaining the web in precise position. In analternate embodiment, the second transfer cylinder 571 does not have avacuum box or vacuum openings and the web is transferred to the secondtransfer cylinder 571 without using vacuum openings.

The second cutting station 441 includes second cutting apparatuscomprising, in one embodiment, a second pair of opposing cutting rolls607, 609 defining a second cutting nip CN2 where the sealed laminatedweb 537 is cut to form individual pads (e.g., pads 1). In thisparticular embodiment, the cutting rolls comprise a lower knife roll 607and an upper anvil roll 609 similar to the two cutting rolls 451, 453 atthe first cutting station 431. Preferably, the knife roll 607 at thesecond cutting station is a vacuum roll having a construction andoperation similar to the first knife roll 451 at the first cuttingstation, except that as shown in FIG. 18, the vacuum boxes 611 at theends of the roll 607 extend over more than about a 180° arcuate segmentalong the upper part of the knife roll from about the 9:00 positionadjacent a fourth transfer nip TN4 between the knife roll 607 and thesecond transfer cylinder 571 to about a 3:00 position for transfer ofthe cut web to a third transfer cylinder 615 at a fifth transfer nip TN5between the knife roll 607 and the cylinder 615. Alternately, the vacuumboxes 611 at the ends of the roll 607 extend over an arcuate segmentalong the upper part of the knife roll from about the 12:00 positionadjacent the second cutting nip CN2 to about a 3:00 position fortransfer of the cut web to the third transfer cylinder 615.

As shown in FIG. 28, the vacuum openings 617 in the outer surface of theknife roll 607 at the second cutting station are arranged and locatedsuch that the laminated web 537 is vacuum gripped and held in preciseposition on the knife roll as the roll rotates in a clockwise directionto pull and convey the web from the fourth transfer nip TN4 to thesecond cutting nip CN2. The knife roll 607 carries cutter blades (ordies) 621 as shown in FIG. 28, for example, spaced at repeatingintervals around the roll. The cutting blades 621 are configured sothat, as the laminated web 537 travels through the second cutting nipCN2, the cover and baffle webs 7W, 9W are cut around the absorbentbodies 5 to form individual pads (e.g., interlabial pads 1). Because thecover and baffle webs are typically of a polymer material, the cuttingblades 621 preferably have an interference fit with the anvil roll 609(i.e., no gap or clearance) at the second cutting nip CN2 to ensure thatthe laminated web is cut completely through. (If different web materialsare used, the clearance at CN2 may vary.) The cutting action formsindividual pads 1 surrounded by remaining scrap portions 625 of the web,sometimes referred to as trim and typically having a ladder-likeappearance. As shown in FIG. 28, the rails of the “ladder”, indicated at627, correspond to the unused extreme side edge margins of the web 537and the rungs of the “ladder”, indicated at 629, correspond to unusedportions of the sealed areas of the laminated web. If required ordesired, resilient inserts similar to the inserts 507 previouslydescribed may be placed inside the cutting blades 621. After cutting atthe nip CN2, the pads 1 and trim 625 are vacuum conveyed by the kniferoll 607 from the second cutting nip CN2 to the fifth transfer nip TN5for transfer to the third transfer cylinder 615.

The third transfer cylinder 615 is essentially identical to the firstand second transfer cylinders 485, 571 except that the vacuum box 635(FIG. 29) inside the third transfer cylinder extends only along anarcuate segment of about 90° on the bottom part of the roll from aboutthe 9:00 position at the fifth transfer nip TN5 to about the 6:00position where the roll forms a sixth transfer nip TN6 with a vacuumconveyor 641 which conveys the pads to the folding section of themachine. Vacuum openings (not shown) in the outer cylindric surface ofthe third transfer cylinder 615 are located and arranged for vacuumgripping the pads 1 transferred from the knife roll 607 and holding themin predetermined positions relative to one another as the transfercylinder 615 rotates in a counterclockwise direction to the sixthtransfer TN6, nip. The gap between the third transfer cylinder 615 andthe vacuum conveyor 641 at the nip TN6 should be no greater than (andpreferably slightly less than) the thickness of the pads 1 to insure aclean separation of the pads from the trim 625 created at the secondcutting nip CN2. The continuous strip of trim material 625 is removedpreferably downstream from the sixth transfer nip TN6 and fed along apath (e.g., at 645 in FIG. 29) to an appropriate waste collector. Thepads 1 are deposited on the conveyor 641 in an unfolded condition inwhich each pad lies flat on the conveyor in a pre-folding position inwhich the baffle web 9W faces up, the cover web 7W faces down, the majoraxis A1 of the pad extends generally parallel to the direction of feed,and the pad is generally centered on the conveyor 641 in a transverse CDdirection with respect to the conveyor.

To maintain the various cutting rolls, sealing rolls, and transfercylinders in timed relationship with one another, they are preferablydriven by a common drive mechanism. This mechanism includes a drivemotor and a drive train connecting the motor to the various rolls andcylinders. The drive train may comprise a series of timing belts andpulleys, for example, or a series of gears or other drive elements, aswill be understood by those skilled in this field.

In the embodiment shown in the drawings, the axial length of each of thecutting rolls, sealing rolls and transfer cylinders is sufficient toaccommodate only one lane of the absorbent bodies and pads. However, itwill be understood that for higher throughput, additional lanes can beestablished by using wider rolls and cylinders, with accompanyingmodifications to associated equipment.

The vacuum conveyor 641 for conveying pads 1 to the folding section 33comprises, in one embodiment (FIG. 30), three endless vacuum belts,namely, a center belt 643 and a pair of side belts 645 trained aroundrollers 647 to have generally horizontal, generally parallel, generallyco-planar upper reaches spaced from one another to define first andsecond slots S1, S2. (FIGS. 30 and 32) The belts are perforated andrelatively narrow, the overall width of the conveyor being notsubstantially greater than the width of an unfolded pad 1 carried by theconveyor so that the side belts 645 support respective side sections 1A,1B of the pad and the center belt 643 supports the center section of thepad. The belts are preferably driven by a common drive 651 (FIG. 30). Avacuum box 653 having vacuum openings 655 in its upper surface ismounted immediately below the upper reaches of the conveyor belts 643,645 and communicates with a vacuum system by means of an air duct (notshown), the arrangement being such that a vacuum is generated at theperforations in the center and side belts to hold each pad in the statedpre-folded position for delivery to the folding station 33. Other meansmay be used for conveying the pads from the pad-making section 31 to thefolding section 33.

Pads delivered to the folding station by the conveyor are folded byfolding apparatus, generally designated 661. In one embodiment (FIGS. 31and 32), this apparatus includes a hold-down member comprising arotatable disc 663 mounted for rotation about a generally horizontalaxis spaced above the vacuum conveyor 641 to define a gap 665 betweenthe peripheral edge of the disk and the upper reach of the center belt643. The hold-down disk 663 preferably rotates in the same direction asthe conveyance of the pads and at about the same speed, and it contactseach pad to hold it down against the center belt 643 as the pad isconveyed through the gap 665 and folded.

The folding apparatus 661 further comprises a plurality of folderscomprising, in one embodiment, two folding disks 671 mounted on oppositesides of the hold-down disc for rotation about a horizontal axis spacedbelow the upper reaches of the belts 643, 645. As shown in FIG. 31, eachfolding disk 671 is formed with ramps 675 at spaced intervals around itsperipheral edge. The ramps 675 on the two disks 671 are adapted toproject up through respective slots S1, S2 between the belts 643, 645and to contact the side sections of the pads 1A, 1B being conveyed asthey pass below the hold-down disk 663. The folding discs 671 preferablyrotate in the same direction as the hold-down disc 663 so that arespective pair of ramps 675 on the two folding disks contact each padas it passes through the gap and fold the side sections 1A, 1B up to aposition in which they face one another, as shown in FIGS. 4 and 32.

Optionally, adhesive may be applied to each pad 1 at an appropriatelocation on the pad (e.g., spot 679 in FIGS. 1 and 3) before it isfolded. One embodiment of this option is shown in FIGS. 30 and 33 ascomprising a glue dispenser 681 having a nozzle 683 for dispensing ametered amount of adhesive (e.g., in bead form) onto an applicator 687positioned immediately above the conveyor 641. In the illustratedembodiment, the applicator 687 is generally rectangular in shape and, inthe orientation shown, has relatively narrow upper and lower edges 691for receiving adhesive from the nozzle 683 of the dispenser 681.

The applicator 687 is rotatable by a driven shaft 693 to rotate in timedrelation to the movement of the pads 1 on the conveyor 641 to apply asmall area of adhesive to the upper surface of each pad at anappropriate location as the pad passes beneath the lower edge 691 of theapplicator carrying the adhesive (see FIG. 33). Preferably, the speed ofthe applicator 687 at its upper and lower edges 691 generallycorresponds with the speed of conveyor 641. The dispenser 681 canoperate intermittently in timed relation to the driven shaft 693 todeliver discrete quantities of adhesive to the upper edge 691 of theapplicator 687 as the lower edge is applying glue to a pad below, or thedispenser can operate continuously to deliver a continuous bead ofadhesive from the nozzle 683 that is picked up by the upper edge of theapplicator as it moves through the bead.

Alternately, the glue dispenser 681 is positioned such that the nozzle683 for dispensing a metered amount of adhesive is located adjacent(e.g., about a distance less than the diameter of a bead of adhesive) tothe pad 1. The dispenser 681 is intermittently actuated to applyadhesive directly to the product. Preferably, a vacuum force holds thepad to a consistent thickness as it passes the nozzle 683 on theconveyor 641. In one embodiment, a glue dispenser commercially availablefrom Nordson Corporation of Westlake, Ohio is used. It will also beunderstood that adhesive may be applied by applicators which have othershapes and/or which operate in different ways. Operation of thedispenser and applicator is controlled by a sensor (e.g., a photocell697) upstream from the dispenser 681 for sensing the presence (or lackof presence) of pads.

To accommodate the application of adhesive to the pads 1, the hold-downdisk 663 has a series of openings (e.g., notches 701) extending inwardfrom its outer edge at spaced intervals around the disc. The notches 701are sized and located to permit the side sections 1A, 1B of each pad tocontact one another at the location of the adhesive spot 679 during thefolding process. The adhesive assists in maintaining each pad in itsfolded condition prior to wrapping of the pad and after the pad isremoved from its wrapper for use.

After the pads 1 are folded, they are conveyed by a suitable conveyormechanism, generally designated 705, in their folded condition to thepackaging section 35 of the machine. In one embodiment (FIG. 34), theconveyor mechanism 705 comprises a pair of endless transport belts 709,711 having spaced apart reaches defining a gap 713 for receiving pads 1delivered from the vacuum conveyor 641 at the folding station 33. Thegap 713 is sized such that the transport belts apply a compressive forceto the pads sufficient to grip and carry them to the packaging section35. In one embodiment, the belts 709, 711 are twisted 90 degrees so thatthey receive the folded pads 1 in a generally vertical orientation andthen rotate the pads 90 degrees for delivery to the packaging section 35in a generally horizontal orientation.

The two transport belts 709, 711 have upstream ends trained around apair of spaced apart generally vertical rollers 717 (FIG. 34) rotatablymounted on a generally horizontal support plate 719 carried by a bracket721 with horizontal slots 723 affixed to the frame of the machine, anddownstream ends trained around a pair of generally horizontal rollers727 rotatably mounted on shafts 729 journalled for rotation in bearinghousings 731 mounted on two brackets 733 with slots 735 affixed to theframe. Preferably, the shafts 723 carry sprockets connected to asuitable variable speed motor (not shown) by a timing belt for rotationof the shafts by the motor. The slots 723, 735 in the various brackets721, 733 allow the positions of the belts 709, 711 to be adjusted invertical and horizontal directions, as needed.

The vertical rollers 717 at the upstream ends of the belts 709, 711 aresecured by threaded fasteners 741 received in transversely extendingslots 743 in the support plate 719, the fasteners being movable in theslots to allow the spacing between the two belts to be adjusted. A pairof belt guide assemblies, each generally designated 747, maintain theupstream ends of the belts 709, 711 in proper position on theirrespective vertical rollers 717. In the embodiment shown in FIG. 34,each assembly 747 comprises a guide roller 751 adapted for contact witha respective belt 709, 711, and a linkage mounting the guide roller 751on the support plate 719.

In the illustrated embodiment, this linkage comprises an L-shaped anglebar 755 affixed to the underside of the support plate 719 by a threadedfastener (not shown) received in a slot 757 in a horizontal leg of theangle bar, an upper tubular arm 761 having a pivot connection 763 with avertical leg of the angle bar, a lower arm 765 having a telescoping fitwith respect to the upper arm 761, a locking collar 767 for securing theupper and lower arms in fixed longitudinal and rotational positionsrelative to one another, and a lever 781 having a pivot connection 783at its lower end with the lower arm 765 and a pivot connection 785 atits upper end with a roller support 787 on which the guide roller 751 isrotatably mounted. This linkage enables the position of the guide roller751 to be adjusted in at least three different dimensions, i.e., in afirst dimension corresponding to the machine direction MD by using theslot 757 in the angle bar 755 to vary the position of the bar relativeto the plate 719; in a second dimension corresponding to the Z directionby pivoting the upper and lower arms 761, 765 about pivot connection 763to raise and lower the guide roller 751; and in a third dimension byrotating the lower arm 765 on its longitudinal axis relative to theupper arm 761 to swing the guide roller 751 to an angled position inwhich its axis of rotation is angled relative to a vertical plane.

By using one or more of these adjustments, the guide roller 751 can bepositioned to contact its respective belt 709, 711 at any orientationnecessary to prevent the belt from “walking” up or down on itsrespective vertical roller 717 and thus maintain the belt substantiallycentered on the roller. The spacing between the belts at theirdownstream ends can be varied by using the slots 735 in brackets 733 toadjust the position of the horizontal rollers 727. The downstream endsof the transport belts are positioned immediately adjacent the packagingsection 35 for delivery of the pads to wrapping apparatus, generallydesignated 801.

Referring to FIGS. 29 and 35, the wrapping apparatus 801 includes aforming device, generally designated 805, for receiving pads deliveredby the transport belts 709, 711, and web-pulling means generallydesignated 807 downstream from the forming device 805 for pulling acontinuous web 811 of flexible wrapping material (e.g., polyethylene orother suitable material) from a supply roll 813 of such material pastthe forming device to wrap the pads 1 in a tube 815 of the materialwhich, when later sealed and cut, will form wrappers for the pads. Thesupply roll of packaging material is supported by a shaft 821 driven bya variable speed motor (not shown) to control the speed at which the webis fed from the roll. The speed of the motor is controlled by aweb-tension sensing device 827 similar to the sensing devices describedearlier for the unwind rolls 425, 427. In the event the sensing devicesenses a change in web tension, it signals the motor to rotate the shaft821 either slower or faster to maintain the speed at which the web 811is pulled from the roll 813 substantially constant.

Referring to FIGS. 36–40, the forming device 805 comprises first andsecond web folding members 831, 833 having angled folding edges 831A,833A adapted for contact by respective opposite side margins M1, M2 ofthe web 811 as the web is pulled past the folding edges (see FIG. 36), aweb guide 837 for guiding the web toward the folding edges, and anopening 839 between the web guide and the folding edges adapted to bespanned by a central portion of the web as the web is pulled past theforming device. In one embodiment, the folding members comprise upperand lower folding plates or boards (also designated 831, 833) havingopposing surfaces defining a relatively narrow gap 843 (FIG. 40)extending in the machine direction MD as the web is pulled over theforming device 805. The folding members 831, 833 also have spaced apartside walls 847 which flare down and out from their respective foldingplates. The folding edges 831A, 833A at the upstream ends of the plates831, 833 are angled in opposite directions relative to the direction ofweb travel and at a suitable angle relative to the direction of webtravel, preferably in the range of from about 14° to about 20° and morepreferably from about 16° to about 18°. The folding members may haveconfigurations other than as described above.

The web guide 837 comprises, in the embodiment shown in FIG. 37, agenerally triangular web contact surface or wall 851 having a base edge853 and opposite side edges 855 which taper up to an apex 857. The wall851 is inclined relative to the plane of the opening 839 and ispositioned for contact by the web 811 of packaging material pulled fromthe supply roll 813. A tongue 861 extends from the apex 857 toward theopening 839. The tongue 861 is preferably either generally coplanar withthe lower folding plate 833 or spaced below the folding plate a verticaldistance less than the thickness of the pad. The web guide also has sidewalls 865 extending in a downstream direction from respective foldingedges 855 to integral junctures with respective side walls 847 of thefolding members. For economy, the web guide and folding members arepreferably formed as a single piece of bent sheet metal (e.g., 14 gauge304 stainless steel sheet) although they may be constructed as separateparts.

As shown in FIGS. 36 and 38, the tapered folding edges 855 of the webguide 837 serve to initiate the folding of the web 811 and to guide itacross the opening 839 toward the folding boards 831, 833 for contact bythe angled folding edges 831A, 833A. A pair of notches 869 extend downfrom the apex 857 of the wall 851 of the web guide on opposite sides ofthe tongue 861. Being under tension, the web 811 deforms down into thesenotches 869 as the web is pulled past the forming device 805.

The wrapping apparatus 801 also preferably includes what may be referredto as a force-applying device which, in the preferred embodiment,comprises a relatively short narrow endless belt 875 extending over theforming device 805 generally along the central portion of the web 811.(The purpose of this belt will be described later.) The belt 875 issupported by a pair of rollers 877, 879, one or both of which are drivento move the belt 875 at the same speed as the web 811 moves past theforming device 805. In the embodiment shown in FIG. 41, the upstreamroller 877 is mounted on a driven shaft 881 rotatable in a bearinghousing 883 secured by a bracket 885 with slots 887 to the frame of themachine. The downstream roller 879 is rotatable in a bearing housing 891carried by a support plate 893. A power actuator (e.g., power cylinder895) is connected to the support plate 873 for pivoting the supportplate and the downstream roller 877 relative to the bearing housing 883to vary the position of the belt 875 as needed for maintenance and foradjustment relative to the forming device 805.

Referring to FIG. 38, the upstream end of the endless belt 875 ispositioned above the web guide 837 to define a gap 901 for receivingpads from the transport conveyor 705. Pads fed one at a time into thegap 901 are carried by the moving web 811 and the belt 875 in themachine direction MD across the opening 839 and past the folding boards831, 833. In the embodiment shown in the drawings, the upstream roller877 of the belt 875 is disposed over the apex 857 and tongue 861 of theweb guide 837, and the downstream roller 879 positioned generally overthe opening 839. The lower reach of the belt 875 is inclined downward inthe machine direction MD and forms an inclined surface which ispositioned for contact by the pads. Thus, as each pad 1 moves past thetongue 861 and over the opening 839, it is forced down against the weband moved to a level where it will pass below the lower folding plate833.

This downward force causes the web in the area of the opening 839 to“cup” so that a pocket or depression 905 is formed in the web forcradling the pads (see FIG. 39). The cupping action is preferablyaccompanied by a resilient deformation or stretching of the web any, ina preferred embodiment, by a resilient compression of the pad, e.g., toa point where the pad has a compressed thickness in the range of 50–100%of the uncompressed thickness of the pad and more preferably about 95%or greater. As a result, the web 811 is tightly wrapped around the padsas the web is pulled past the folding edges 831A, 833A of the foldingplates 831, 833 to form the aforementioned tube 815 around the pads. Inaddition to applying a downward force in Z direction, the frictionbetween the belt 875 and the pads 1 subjects the pads to a pushing forcein the machine direction MD to assist in the movement of the pads towardthe folding boards.

FIGS. 38A–38C illustrate an alternate force-applying device, generallydesignated 918, for applying a downward force on the pads. The device ispositioned above the web guide 837 and comprises a hold down plate 920having downwardly extending side flanges 921 which define a channel 922for receiving pads from the transport conveyor 705. Pads fed one at atime into the channel 922 are carried by the moving web 811 in themachine direction MD across the opening 839 and past the folding boards831, 833. In the embodiment shown in the drawings, the hold down plate920 has a lower surface which is inclined downward in the machinedirection MD and is positioned for contact by the pads. Thus, as eachpad 1 moves past the tongue 861 and over the opening 839, it contactsthe lower surface of the hold down plate 920 and is forced down againstthe web 811 and moved to a level where it will pass below the lowerfolding plate 833 as explained above.

As illustrated in FIG. 38A, the hold down plate 920 is carried at thelower end of a rigid arm having an upper end pivoted at 924 to the frameof the machine for movement between a lowered position as shown in FIG.38A in which the hold down plate is properly positioned with respect tothe web guide 837, and a raised position (not shown), the two ranges ofpivotal movement being established by two stops 936, 938. A torsionspring 928 urges the arm toward its lowered position. In one embodiment,a proximity switch (not shown) is mounted adjacent the arm 923. Abacked-up or jammed condition of pads 1 in the channel 922 causes anupward force on the hold down plate 920 and a corresponding movement ofthe arm 923 against the bias of the spring 928. This movement triggersthe proximity switch, alerting operators of the jammed condition orstops the movement of transport conveyor 705.

Preferably, as shown in FIGS. 38B and 38C, the device 918 also includesa plenum member (e.g., plate 930) which overlies the hold down plate 920and defines a plenum chamber above the plate, and an air fitting 929 onthe plenum member 930 for supply of pressurized air from a suitablesource to the plenum chamber. The hold down plate 920 is perforated withair holes 934 through which air is directed to form an air film betweenthe hold down plate 920 and the pads 1 as they pass beneath the plate.The air film reduces friction between the pads and the hold down plate920 as the pads move toward the folding boards 831, 833. Additionally,it will be understood that other devices may be used for applying thestated pressing force on the pads.

The web guide 837, opening 839 and folding members 831, 833 shown in thedrawings can assume other shapes without departing from the scope ofthis invention. For example, the length and shape of the tongue 861 canvary. Further, the size of the opening 839 can vary, although it ispreferred that the opening have a width W in the cross direction CD(transverse to the direction of web travel) about 97% of the width ofeach of the pads, and a length L in the machine direction MD of about18% of the length of each pad.

The position of the forming device 805 is preferably adjustable in themachine direction MD, cross direction CD, and Z direction. While thisadjustment can be achieved in various ways, one such way is illustratedin FIG. 35. In this particular embodiment, the forming device 805 ismounted on a post 909 affixed at its lower end to a channel 911extending in the machine direction MD. The channel, in turn, is attachedto a cross rail 915 which is supported by a mounting plate 917 withslots 919 fastened to the frame of the machine. The channel and rail911, 915 are provided with fastener openings to permit adjustment of theforming device in the MD and CD directions, and the slots 919 providefor adjustment of the device in the Z direction. Thus, the position ofthe forming device can be adjusted in the MD, CD and Z directions, asneeded.

Referring to FIG. 38, an adhesive applicator, generally designated 925,is provided at the forming device 805 for applying a suitable adhesiveto at least one margin M1, M2 of the web 811 before or as it is foldedto secure the tube 815 around the pads 1 after exit from the formingdevice 805. In one embodiment, the applicator 925 comprises a gun 927capable of dispensing a suitable adhesive (e.g., a hot-melt glue)through a nozzle 931 positioned close to the web 811 (e.g., within 0.003to 0.004 in.) for the transfer of adhesive to margin M1 of web as theweb moves past the nozzle 931 and before the margin is overlapped withthe opposite margin M2 of the web. Preferably, the nozzle transfers acontinuous bead or stripe of adhesive to the web, as indicated at 933 inFIGS. 36 and 40, but it will be understood that the adhesive may beintermittently applied in the web, if desired. The adhesive dispensedfrom the nozzle 931 is preferably in extruded bead form, but it may alsobe sprayed. In one embodiment, an air supply line 932 provides apressure source to open the gun 927 and an air supply line 934 providesa pressure source to close the gun 927.

In the embodiment shown in FIGS. 42–44, the applicator further comprisesa housing 935 connected to an adhesive supply line 937 for the deliveryof adhesive to the gun and, optionally, to a pressure air line 939(e.g., 20 psi air) for the delivery of air under pressure for dispensingof the adhesive through the nozzle 931. The position of the nozzle isadjustable in the Z direction to vary the spacing between the nozzle andthe web, as needed.

FIGS. 42–44 illustrate one possible way to achieve this adjustment. Inthis particular embodiment, the housing 935 of the applicator isattached by means of a bracket 945 with slots 947 to a crosshead 949bridging the piston rods 953 of a power actuator 957. The actuator, inturn, is mounted on a tongue 961 slidable in a vertical groove 963 in amounting block 965 attached to an L-shaped bracket 967 affixed to theframe. A screw shaft 971 (FIG. 44) rotatable in the mounting block 965extends through a threaded bore 971 in the tongue 961, the arrangementbeing such that rotation of the screw draft 971 by a handwheel 975causes the tongue and actuator 957 to move in a vertical direction.Thus, the position of the adhesive applicator 925 in the Z direction canbe roughly adjusted by extension and retraction of the piston rod 953,and more finely adjusted by rotation of the handwheel 975.

When the spacing between the nozzle 931 and the web 811 is set, athumbscrew 979 threaded through a bar 981 affixed to the bracket 967 istightened against the handwheel 975 to lock the screw shaft 971 againstrotation until a further adjustment is needed. The bracket 967 holdingthe mounting block 965 has horizontal slots 985 (FIG. 42) to enable theposition of the nozzle 931 to be varied in the CD direction extendingtransversely of the web. Adjustment in the MD direction is effected bymeans of slots 947. Other mechanisms can be used to provide foradjustment of the position of the applicator 925 relative to the web811.

Alternatively, the adhesive gun 927 can be positioned for dispensingadhesive for application to the opposite margin M2 of the web after ithas been folded over to a position overlying the pads but before marginM1 has been folded face-to-face with M2. A notch (not shown) may beprovided in the lower folding board 833 for this purpose. A portion ofthis notch extends upstream from the angled folding edge 831A of theupper folding board 831, leaving the folded-over margin M2 of the webexposed for application of an adhesive from the gun 927. After theadhesive is applied, the upper folding board 831 folds the other marginM1 of the web over the underlying margin M2 as the web is pulled pastthe folding boards.

The web-pulling means 807 for pulling the web 811 past the formingdevice 805 comprises, in one embodiment (FIGS. 35 and 45), a vacuumconveyor, generally designated 1001, in the form of an endlessperforated belt 1003 (the perforations being omitted in FIG. 45 forsimplicity) trained around upstream and downstream rollers 1007, 1009,at least one of which (e.g., roller 1007) is rotated by a drive shaft1011 mounted in a bearing housing 1013 secured to a bracket 1015 on theframe. A vacuum box or manifold 1019 is supported on the frame below theupper reach of the belt 1003 and has openings 1021 in its upper surfacefor drawing a vacuum through the belt to grip the tubular wrapper 815formed by forming device 805, thus providing the force necessary forpulling the web 811 in the machine direction MD over the forming deviceand for feeding the tubular wrapper containing the pads to a wrappersealing station 1025 downstream from the forming device 805.

The conveyor 1001 also includes an upper endless compression belt 1027supported by upstream and downstream rollers 1029 and 1033,respectively. As shown in FIG. 45, the upstream roller 1029 is driven bya shaft 1035 rotatable in a bearing housing 1039 affixed to a bracket1041 fastened to the frame of the machine. The downstream roller 1033 issupported by a shaft 1041 journalled in a bearing plate 1045 having apivot connection 1047 with the bearing housing 1039. The bearing plate1045 is pivotable about the connection by means of a power actuator(e.g., cylinder 1051) to move the compression belt 1027 between alowered position in which the lower reach of the belt is substantiallyparallel or having a small decline with respect to the upper reach ofthe lower belt 1003, as shown in FIG. 35, and a raised position as shownin FIG. 45. When in its lowered position, the compression belt 1027applies a compressive force to the tubular wrapper 815 to press theoverlapping margins M1, M2 of the wrapper together to form a goodadhesive seal along the tube, and also to assist in the feed of thewrapper in the machine direction MD. The compression belt 1027 can beraised when not in use, as for maintenance.

Sealing apparatus, generally designated 1100 in FIG. 35, is provided atthe sealing station 1025 for sealing the tubular wrapper 815 between thepads 1 in seal areas 1103 extending transversely with respect to thetube 815 in the CD direction (see FIG. 46). Referring now to FIGS. 35and 47, the sealing apparatus 1100 comprises upper and lower sealingrolls indicated at 1107 and 1109, respectively, each of which carries aplurality of sealing jaws 1113 extending axially along the circumferenceof the roll at spaced intervals around the roll (e.g., six sealing jawsat 600 intervals around the roll). Each jaw 1113 comprises a base 1117fastened to the roll in conventional fashion, as by threaded fasteners1119, and a sealing bar 1121 projecting out from the base having aheated sealing area 1125.

A heating element (not shown) is embedded in the bar for heating thesealing area 1125 of the bar to a temperature sufficient to soften thewrapper material. The rolls 1107, 1109 are driven by suitable drivemechanisms 1131 to rotate in timed and synchronized relation to oneanother so that the heated sealing jaws 1113 on the two rollssequentially move into registration with one another and simultaneouslycontact opposing (e.g., upper and lower) surfaces of the tubular wrapper815 at intervals spaced along the web to press the surfaces together andform the seal area 1103 between the pads, as will be understood by thoseskilled in this field. The operation of the heating elements iscontrolled by temperature sensors embedded in the sealing bars 1121adjacent the heating elements. Preferably, the sealing areas 1125 of thesealing bars 1121 are textured (e.g., roughened) to mechanically deformthe opposing surfaces of the tubular wrapper 815 and thus establish amechanical bond between the surfaces to hold them together prior tocomplete cooling of the seal. A supporting surface 1131 is providedimmediately upstream of the sealing rolls 1107, 1109 for supporting thetubular wrapper as it enters the nip of the rolls.

The tubular wrapper 815 is pulled between the two sealing rolls 1107,1109 by suitable means, such as a pair of upper and lower endless belts1135, 1137 similar to the endless belts 1003, 1027 previously describedimmediately upstream from the sealing station 1025. These belts 1135,1137 may also function to feed the sealed wrapper 815 to a cuttingstation 1041 where cutting apparatus 1043 is provided for cutting thesealed tubular wrapper at the seal areas 1103 to form individual wrappedpads.

Referring to FIG. 29, the cutting apparatus 1043 comprises, in oneembodiment, a pair of upper and lower cutting rolls designated 1051 and1053, respectively. The construction of these rolls is similar to thatof the sealing rolls 1107, 1109, except that the sealing jaws on oneroll are replaced by cutting blades and the sealing jaws on the otherroll are replaced by anvil bars which support the web for cutting by theblades, in a conventional manner. Rotation of the cutting rolls 1051,1053 is timed and synchronized to cut through the tubular wrapper 815 atthe seal area 1103. As shown schematically in FIG. 46, the cut 1061across each seal area is generally at the middle of the seal (in themachine direction MD) so that one cut simultaneously forms the trailingseal of one wrapper and the leading seal of the following wrapper. Theindividually wrapped pads are then discharged into a suitable receptacle1065 (FIG. 16) or onto a conveyor for transport to an optional collatingstation where the pads may be grouped by hand or by a suitable collatingmechanism for further packaging in cartons or the like.

The operation of the apparatus described above to carry out the methodsof the invention will now be described. Raw fibers (e.g., cotton andrayon) are weighed out and mixed in the desired proportion in the fiberblending section 21 of the system. This process is initiated by loadingfibers of one material (e.g., cotton) on the in-feed conveyor 67 of thefirst weighing apparatus 41 (see FIG. 7) for delivery to its respectiveweigher 77, and by loading fibers of another material (e.g., rayon) onthe in-feed conveyor of the second weighing apparatus 43 for delivery toits respective weigher. The weighers 77 are operable to weigh outquantities of these fibers in correct proportion by weight (e.g., 1120grams of cotton and 480 grams of rayon) and to unload them onto theconveyor 91 for delivery to the blend opener 47.

In one embodiment, the unloading is timed so that the downstream weigher77 unloads its weighed-out batch of fibers directly on top of the batchunloaded by the upstream weigher 77, so that a single pile of fiberscontaining the correct proportions of fibers is delivered to the blendopener 47 (see FIG. 8). Fibers fed into the blend opener are opened andmixed, to some extent, and then transported through air duct 49 to theair separator 51 (FIG. 9). There, the air and fiber fines are separatedfrom the longer fibers and delivered to the fines collector 57. Thelonger fibers are conveyed to the rotary air lock 144 which rotates atthe necessary speed to feed the longer fibers to the inlet of the fineopener 55 at the desired rate. The fine opener 55 (FIG. 10) furtherseparates and mixes the fibers and delivers them to the feed chute 221via the air duct 61.

The fibers entering the inlet section 229 of the feed chute 221 (FIG.11) are entrained in a stream of air and directed into the upper chute231 where they collect above the feed and beater rolls 245, 247. Airentering the upper chute 231 exits through the porous wall 237 of thechute. The feed and beater rolls 245, 247 rotate to perform a separationand blending operation on the fibers before they are delivered to theaccumulation chute 263 in a substantially separated (“opened”) and mixedcondition, with the fibers of one type being blended with the fibers ofthe other type. The feed of the fibers down in the accumulation chute263 is assisted by the oscillation of the shaker plate 267. Further, thefrequency and amplitude of the oscillation can be varied to control thedensity of the fibers delivered to the compression rolls 291 adjacentthe outlet 227 of the feed chute.

As the fibers pass between these two rolls 291, they are formed into alayer 295 of desired thickness for deposit on the transfer device 301leading to the forming section 27 of the machine (FIG. 13). Thethickness of the layer 295 and the speed at which it is delivered iscontrolled by the size of the gap 293 between the compression rolls 291and the speed of the rolls, respectively. For example, the layer 295 mayhave a thickness of about 2 in. and the rolls may have a surface speedof about 6 fpm. The density of the layer 295 (e.g., weight per unitlength) is controlled at least in part by the height of the column offibers in the accumulation chute 263, the amplitude and frequency of theoscillation of the shaker plate 267, the compressive force applied bythe compression rolls 291, and the speed of the rolls 291. Preferably,the density of the fibers discharged from the feed chute 221 is in therange of 0.005–0.16 g/cc, more preferably in the range of 0.010–0.030g/cc, and even more preferably in the range of 0.013–0.019 g/cc. Thelayer 295 of blended fibers delivered from the feed chute 221 may berelatively wide, e.g., 40 in. wide, although this dimension may varyconsiderably. If sufficiently compacted, the layer 295 may be in theform of an integral web capable of independently maintaining its bodyand shape. However, the layer may also be a thickness of looselycompacted (or non-compacted) fibers combining to form a body the shapeof which is not self-sustaining.

The layer 295 of fibers from the feed chute 221 gravitates down theslide 301 (or is conveyed in some other manner, as by an endlessconveyor) for delivery to the gap 319 between the feed roll 315 and theadjacent guide surface 317, as shown in FIG. 14. The rotating feed roll315 serves to feed the layer 295 of blended fibers to the fiberizingroll (e.g., lickerin roll 321) which breaks up the fibers. After thisfiberizing operation, the fibers fall and are swept into the inlet ofthe air chamber 347 where they are air laid onto the forming surface 337of the conveyor 335 and reformed into a layer 343 having a widthgenerally corresponding to the final width of the absorbent body in thepad (e.g., body 5 in pad 1). As noted previously, the fibers making upthis reformed layer 343 are randomly oriented and blended into asubstantially homogenous mixture having strength in MD and CDdirections, and further having the ability to effectively absorb anddistribute fluid deposited on the material. The thickness of thereformed layer 343 is controlled by the speed of the reforming conveyor335, which is variable, and by the amount of fibers delivered into theair chamber 347 for deposit on the foraminous forming surface 337 of theconveyor.

As thus reformed, the layer 343 is transported to the compression belt401 where the fibers are lightly compressed, and then to the compressionrolls 407, 409 where the fibers are more severely compressed into theaforementioned continuous web 417 of absorbent material having athickness generally corresponding to the thickness of the absorbent body(e.g., body 5) in the final product (FIG. 17). The compression belt 401may be eliminated, if not needed. The thickness of the web 417 iscontrolled primarily by the spacing between the two compression rolls407, 409. Following compression, the web is conveyed to the pad-makingsection 31 of the system.

At the pad-making section (FIG. 18), the web 417 is fed in the machinedirection MD between the two cutting rolls 451, 453 at the first cuttingstation 431, where the web is cut to form individual absorbent bodies 5,an exemplary shape of which is illustrated in FIG. 20. The web is thenvacuum conveyed by the knife roll 451 to the first transfer nip TN1where the absorbent bodies are transferred to the first transfercylinder 485, while maintaining the bodies in precise position relativeto one another. The trim (waste material) 491 from the cutting operationis preferably removed after the transfer by means of the vacuum duct 493for delivery of the trim to a suitable collector, not shown. Meanwhile,the absorbent bodies 5 are vacuum conveyed by the first transfercylinder 485 to the second transfer nip TN2.

The cover web 7W is also fed from the unwind roll 425 to the secondtransfer nip TN2, where bodies 5 are successively transferred from thefirst transfer cylinder 485 to positions on the cover web overlyingrespective pockets 553 in the sealing roll 541. The bodies 5 andunderlying web 7W are drawn by the vacuum openings 561 into the pockets553 and held in place as they are conveyed to the sealing nip SN. If abaffle web 9W is used, it is combined with the cover web 7W andabsorbent bodies 5 at the sealing nip SN, as described previously (FIG.19), and the sealed laminated web 437 is then vacuum conveyed to thethird transfer nip TN3 where it is transferred to the second transfercylinder 571. The second transfer cylinder 571 vacuum grips thelaminated web and conveys it to the fourth transfer nip TN4 where theweb 437 is transferred to the lower cutting roll 607 for vacuumconveyance of the web to the second cutting nip CN2 at the secondcutting station 441. There, the two cutting rolls 607, 609 cut thelaminated web 437 around the absorbent bodies 5 to form individual pads(e.g., pads 1) which are held by the vacuum openings 617 in the lowerroll 607 as the web is conveyed to the fifth transfer nip TN5. The pads1 are transferred at TN5 to the third transfer cylinder 615, whichconveys the pads and deposits them on the 3-belt vacuum conveyor 641 inan orientation where the pads preferably lie flat on the conveyor withthe baffle layer 9 of the pad facing up (if a baffle layer is used),with the central section of the pad supported by the center belt 643,and with the side sections 1A, 1B of the pad supported by the side belts645. The trim or waste portion of the web (indicated at 625 in FIG. 28)is removed by allowing the trim to follow around the third transfercylinder 615 for delivery to a suitable collector, or by pulling itstraight down from the fifth transfer nip TN5 for disposal.

The vacuum conveyor 641 conveys the pads 1 to the folding section 33while maintaining the pads in fixed positions relative to one another.At the folding section (FIG. 30) the side sections 1A, 1B of each padare folded up by the two folding disks 671 while the center section ofthe pad is held down by the hold-down disk 663. As thus folded, the padappears as shown in FIG. 3, with the pad preferably lying in a generallyupright (e.g., vertical) orientation. Prior to folding, an adhesive suchas a hot-melt glue may be applied to the upper surface of the pad (e.g.,the baffle layer 9) by the applicator 687, so that when the two sidesections 1A, 1B are folded face to face, the adhesive will secure thepad in its folded condition. After each pad 1 is folded, and while it isstill being held upright by the folding disks 663, it is fed into thegap 713 between the transport belts 709, 711 for conveyance to thepackaging section 35 (FIG. 34). The 90° twist in the belts 709, 711functions to rotate the pads 1 to a generally horizontal orientation fordelivery to the forming device 805. The position of the guide rolls 751can be adjusted, if necessary, to maintain the twist belts properlycentered on the vertical rollers 717 at the upstream ends of the belts.

At the packaging section 35, the web 811 of flexible wrapping materialis pulled over the forming device 805 by the web-pulling means 807, withthe web first advancing over the web guide 837 and then past the foldingboards 831, 833 (see FIGS. 36 and 38). As the web 811 is pulled over theforming device, pads 1 are fed from the transport belts 709, 711, one ata time, into the gap 901 between the tongue 861 of the web guide and theoverhead belt 875, the latter moving at the same speed as the web. Aseach pad enters this gap, it is conveyed with the web in the machinedirection MD over the opening 839 between the tongue 861 and the foldingboards 831, 833. As the pad moves over the opening 839, the downwardlyinclined lower reach of the belt 875 applies a force on the pad 1 topress it into the central portion of the web 811, causing the web to cupand, preferably, to stretch somewhat in the cross direction CD, as bestillustrated in FIG. 39. This cupping of the web creates a volume in theweb, i.e., a depression or groove or pouch 905, to begin the formationof the tubular wrapper 815 around the pad. The force applied to the pad1 is sufficient to cause the web 811 and underlying central portion ofthe web to move down to a position where the top of the pad will clearthe lower folding board 833. This position can be adjusted by operationof the power cylinder 895 to pivot the belt 879 up or down relative tothe folding device 805. As noted previously, other force-applyingdevices (e.g., an inclined stationary surface) can be used to initiatethe formation of the tubular wrapper 815 around the pads.

As the pad 1 and central portion of the web 811 move below the lowerfolding board 833, the side margins M1, M2 of the web engage respectivefolding edges 831A, 833A of the folding boards and are folded into faceto face relation, as shown in FIG. 40, to form the tubular wrapper 815around the pad. In the embodiment shown in FIG. 40, the side margins M1,M2 of the web are folded so that the facing surfaces of the margins areconstituted by opposite faces of the web 811 to form a so-called overlapseam on the tube 815. However, it will be understood that the sidemargins M1, M2 could be folded to make a fin seam where the facingsurfaces of the margins are constituted by the same face of the web 811.In either event, adhesive 933 is applied to at least one of the sidemargins M1, M2 by the applicator 925 before the margins are folded intoface to face relation, the adhesive being on the surface of the sidemargin which will eventually face the opposing side margin after thefolding operation is complete. The spacing between the nozzle 931 of theapplicator 925 and the surface of the web 811 to which the adhesive isapplied is preferably such that the web draws a continuous bead ofuniform volume (or a series of intermittent spots of uniform volume)from the nozzle as the web passes the nozzle. Alternatively, theadhesive may be sprayed or otherwise applied to the web 811.

The tubular wrapper 815 containing the pads 1 is pulled in the machinedirection MD by the vacuum belt 1003 (FIG. 45), which in the preferredembodiment provides the primary force for pulling the web 811 over theforming device 805. As the newly-formed tubular wrapper 815 passesbetween the vacuum belt 1003 and the overhead compression belt 1027, itis subjected to a compressive force to adhere the side margins M1, M2 ofthe web together to form a longitudinal seam extending the length of thetubular wrapper before the tube is fed between the two sealing rolls1107, 1109 at the sealing station 1025. As the two sealing rolls rotate,the sealing bars 1121 on the upper roll 1107 move into sequentialregistration with the sealing bars 1121 on the lower roll 1109 to sealthe tube in the seal areas 1103 between the pads (see FIG. 46). Thetubular wrapper tube containing the pads is pulled through the sealingstation 1025 by the vacuum belt 1137 and compression belt 1135downstream from the sealing station. These belts also serve to feed thesealed tube to the cutting station 1041 where the cutting rolls 1051,1053 cut across the tube at the sealed areas 1103 to form individuallywrapped pads. As noted previously, further packaging operations can beperformed, if desired.

For efficiency, the various sections of the apparatus of the inventionshould be run at compatible speeds which enable substantially continuousoperation (at least 85% of the time) of all sections withoutinterruption. That is, upstream sections should not be run atexcessively high speeds which will exceed the capacity of downstreamsections, nor at excessively slow speeds which will starve thedownstream sections.

While the apparatus and methods have been described in the context ofmaking interlabial pads of the type shown in FIG. 1, the features of theinvention can be used to make other types of articles, absorbent orotherwise.

When introducing elements of the invention or the preferredembodiment(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions and methodswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

1. A method of blending first and second fibers, said method comprising: conveying a supply of first fibers to a first weigh station; conveying a supply of second fibers to a second weigh station; weighing out and discharging a first quantity of the first fibers; weighing out and discharging a second quantity of the second fibers; and conveying the first and second quantities of fibers to a blend opener; opening and blending the first and second quantities of fibers with a first rotatable roll in said blend opener; entraining said blended fibers in an air stream to convey said blended fibers from said blend opener to a fine opener; and further opening and mixing the fibers with a second rotatable roll in said fine opener.
 2. The method of claim 1 further comprising separating fiber fines from longer fibers of said blended fibers before opening and mixing the blended fibers in said fine opener.
 3. The method of claim 1 further comprising substantially separating the blended fibers from the air stream before opening and mixing the blended fibers in said fine opener.
 4. The method of claim 1 further comprising feeding the blended fibers as an initial layer of blended fibers, breaking up said initial layer into small tufts and individual fibers at a fiberizing station, and reforming the small tufts and individual fibers as a reformed layer of blended fibers on a moving conveyor. 